We have accomplished various Investigations described below for the establishment of the basis of 'Protein Engineering'.1, The approach by replacing amino acid : (1) Glu23 residue of T4 endonuclease was proved to be Important in glycosylase activity. (2) Thrl56 residue of H^+ ATPase was found to be important to evoke activity. (3) The structure-function relationship of NADHcytochrome b_5 was examined to understand the cause of hereditary methemoglobinemia. (4) The role of Trp108 in lysozyme on evoking activity became apparent.2, The approach by constructing expression system of aimed protein : (1) The binding site of bovine tissue factor was present in the region between Gal and EGF domain in blood coagulation factor VII. (2) The active sites and the catalytic mechanism of neutral protease from Bacillus subtilis var. amylosacchariticus were elucidated. (3) The binding mode of L-lysine and ATP with lysyl tRNA synthase from Bacillus stearothermophilus were analyzed.3, The approach by com
… Moreparing primarx and tertiary structure of proteins : (1) HIs210 residue of lysylendopeptidase was proved to be important in high-selectivity on evoking activity. (2) The relationship between structure and function in phospholipase A_2 from Habu snake was analyzed. (3) The catalytic mechanism of human aldolase was analyzed by preparing its various chimeric proteins. (4) The structure, function and heredity of both triosephosphate isomerase and ribonuclease were examined discussed by the analysis of their module structures.4, The approach by means of chemical modification : (1) RNase T1 and trypsin became stable by introducing novel polyethyleneglycol and amylose derivative.5, The approach by use of NMR and X-ray crystallography : (1) The allosteric phenomena of L-lactic acid dehydrogenase from Bifidobacterium longum was analyzed. (2) The tertiary structure of neocarzinostatin was determined by use of NMR and distance geometry algorism. (3) The function of Bowman-Birk protease inhibitor was examined from the X-ray crystallographic analysis of its complex with trypsin. Less